

2018 . 

Bulletin of Iranian Mathematical Society
ISSN 1017060X
دوماهنامه  ( )
2 2017




 Flagtransitive pointprimitive (v,k,4) symmetric designs with exceptional socle of Lie type Y. Wang , S. Zhou* Pages 259273 Abstract Full Text [PDF 149KB]   Let G be an automorphism group of a 2(v،k،4) symmetric design D. In this paper، we prove that if G is flagtransitive pointprimitive، then the socle of G cannot be an exceptional group of Lie type.
Keywords: Symmetric design; flagtransitive; pointprimitive; exceptional simple group
  
 Connections between labellings of trees B. Yao* , X. Liu , M. Yao Pages 275283 Abstract Full Text [PDF 109KB]   There are many longstanding conjectures related with some labellings of trees. It is important to connect labellings that are related with conjectures. We find some connections between known labellings of simple graphs.
Keywords: trees; (odd)graceful labellings; felicitous lalbellings; (k; d)graceful labellings
  
 Arens regularity of bilinear maps and Banach modules actions A. Sahleh * , L. Najarpisheh Pages 285289 Abstract Full Text [PDF 84KB]   Let X، Y and Z be Banach spaces and f:XY⟶Z a bounded bilinear map. In this paper we study the relation between Arens regularity of f and the reflexivity of Y. We also give some conditions under which the Arens regularity of a Banach algebra A implies the Arens regularity of certain Banach right module action of A.
Keywords: Banach algebra; bilinear map; Arens product; second dual; Banach module action
  
 Multipliers of continuous Gframes in Hilbert spaces M. R. Abdollahpour * , Y. Alizadeh Pages 291305 Abstract Full Text [PDF 134KB]   In this paper we introduce continuous gBessel multipliers in Hilbert spaces and investigate some of their properties. We provide some conditions under which a continuous gBessel multiplier is a compact operator. Also، we show the continuous dependency of continuous g Bessel multipliers on their parameters.
Keywords: gframes; continuous frames; continuous gframes; Multiplier of frames; Multiplier of continuous gframes
  
 Study on multiorder fractional differential equations via operational matrix of hybrid basis functions K. Maleknejad * , K. Nouri , L. Torkzadeh Pages 307318 Abstract Full Text [PDF 140KB]   In this paper we apply hybrid functions of general blockpulse functions and Legendre polynomials for solving linear and nonlinear multiorder fractional differential equations (FDEs). Our approach is based on incorporating operational matrices of FDEs with hybrid functions that reduces the FDEs problems to the solution of algebraic systems. Error estimate that verifies a convergence of the approximate solutions is considered. The numerical results obtained by this scheme have been compared with the exact solution to show the efficiency of the method.
Keywords: Fractional derivatives and integrals; multiorder fractional differential equations; operational matrix; hybrid functions
  
 A new result on chromaticity of K4homoemorphs with girth 9 N.S.A. Karim , R. Hasni * , G.C. Lau Pages 319336 Abstract Full Text [PDF 159KB]   For a graph G، let P(G،lambda) denote the chromatic polynomial of G. Two graphs G and H are chromatically equivalent if they share the same chromatic polynomial. A graph G is chromatically unique if any graph chromatically equivalent to G is isomorphic to G. A K4homeomorph is a subdivision of the complete graph K4. In this paper، we determine a family of chromatically unique K4 homeomorphs which have girth 9 and has exactly one path of length 1، and give sufficient and necessary condition for the graphs in this family to be chromatically unique.
Keywords: Chromatic polynomial; chromatically unique; K4homeomorphs
  
 Extrinsic sphere and totally umbilical submanifolds in Finsler spaces B. Bidabad * , M. Sedaghat Pages 337347 Abstract Full Text [PDF 117KB]   Based on a definition for circle in Finsler space، recently proposed by one of the present authors and Z. Shen، a natural definition of extrinsic sphere in Finsler geometry is given and it is shown that a connected submanifold of a Finsler manifold is totally umbilical and has nonzero parallel mean curvature vector field، if and only if its circles coincide with circles of the ambient manifold. Finally، some examples of extrinsic sphere in Finsler geometry، particularly in Randers spaces are given.
Keywords: Finsler space; development; mean curvature; umbilical; extrinsic sphere
  
 Strong convergence theorem for solving split equality fixed point problem which does not involve the prior knowledge of operator norms Y. Shehu* , F. U. Ogbuisi , O. S. Iyiola Pages 349371 Abstract Full Text [PDF 643KB]   Our contribution in this paper is to propose an iterative algorithm which does not require prior knowledge of operator norm and prove a strong convergence theorem for approximating a solution of split equality fixed point problem for quasinonexpansive mappings in a real Hilbert space. So many have used algorithms involving the operator norm for solving split equality fixed point problem، but as widely known the computation of these algorithms may be difficult and for this reason، some researchers have recently started constructing iterative algorithms with a way of selecting the stepsizes such that the implementation of the algorithm does not require the calculation or estimation of the operator norm. To the best of our knowledge most of the works in literature that do not involve the calculation or estimation of the operator norm only obtained weak convergence results. In this paper، by appropriately modifying the simultaneous iterative algorithm introduced by Zhao، we state and prove a strong convergence result for solving split equality problem. We present some applications of our result and then give some numerical example to study its efficiency and implementation at the end of the paper.
Keywords: Strong convergence; split equality fixed point problem; quasinonexpansive mappings; simultaneous iterative algorithm; Hilbert spaces
  
 Triple positive solutions of mpoint boundary value problem on time scales with pLaplacian A. Dogan* Pages 373384 Abstract Full Text [PDF 126KB]   In this paper، we consider the multipoint boundary value problem for onedimensional pLaplacian dynamic equation on time scales. We prove the existence at least three positive solutions of the boundary value problem by using the Avery and Peterson fixed point theorem. The interesting point is that the nonlinear term f involves a firstorder derivative explicitly. Our results are new for the special cases of difference equations and differential equations as well as in the general time scale setting.
Keywords: Time scales; Boundary value problem; pLaplacian; positive solutions; fixed point theorem
  
 New classes of Lyapunov type inequalities of fractional Δdifference SturmLiouville problems with applications K. Ghanbari * , Y. Gholami Pages 385408 Abstract Full Text [PDF 175KB]   In this paper، we consider a new study about fractional Δdifference equations. We consider two special classes of SturmLiouville problems equipped with fractional Δdifference operators. In couple of steps، the Lyapunov type inequalities for both classes will be obtained. As application، some qualitative behaviour of mentioned fractional problems such as stability، spectral، disconjugacy and some interesting results about zeros of (oscillatory) solutions will be concluded.
Keywords: Discrete fractional calculus; discrete fractional SturmLiouville problem; Lyapunov type inequalities; stability; MittagLeffler type functions
  
 Some extended Simpsontype inequalities and applications K. C. Hsu , S. R. Hwang , K. L. Tseng* Pages 409425 Abstract Full Text [PDF 142KB]   In this paper، we shall establish some extended Simpsontype inequalities for differentiable convex functions and differentiable concave functions which are connected with HermiteHadamard inequality. Some error estimates for the midpoint، trapezoidal and Simpson formula are also given.
Keywords: HermiteHadamard inequality; Simpson inequality; midpoint inequality; trapezoid inequality; convex function; concave functions; special means; quadrature rules
  
 Left derivable or Jordan left derivable mappings on Banach algebras Y. Ding , J. Li * Pages 427437 Abstract Full Text [PDF 114KB]   Let A be a unital Banach algebra، M be a left Amodule، and W in Z(A) be a left separating point of M. We show that if M is a unital left Amodule and δ is a linear mapping from A into M، then the following four conditions are equivalent: (i) δ is a Jordan left derivation; (ii)δ is left derivable at W; (iii) δ is Jordan left derivable at W; (iv)Aδ(B)+Bδ(A)=δ(W) for each A،B in A with AB=BA=W. Let A have property (B) (see Definition ???)، M be a Banach left Amodule، and δ be a continuous linear operator from A into M. Then δ is a generalized Jordan left derivation if and only if δ is Jordan left derivable at zero. In addition، if there exists an element C∈Z(A) which is a left separating point of M، and RannM(A)={0}، then δ is a generalized left derivation if and only if δ is left derivable at zero.
Keywords: (Jordan) left derivation; generalized (Jordan) left derivation; (Jordan) left derivable mapping
  
 The Steiner diameter of a graph Y. Mao* Pages 439454 Abstract Full Text [PDF 172KB]   The Steiner distance of a graph، introduced by Chartrand، Oellermann، Tian and Zou in 1989، is a natural generalization of the concept of classical graph distance. For a connected graph G of order at least 2 and S⊆V(G)، the Steiner distance d(S) among the vertices of S is the minimum size among all connected subgraphs whose vertex sets contain S. Let n،k be two integers with 2≤k≤n. Then the Steiner keccentricity ek(v) of a vertex v of G is defined by ek(v)=max{d(S)S⊆V(G)،S=k،andv∈S}. Furthermore، the Steiner kdiameter of G is sdiamk(G)=max{ek(v)v∈V(G)}. In 2011، Chartrand، Okamoto and Zhang showed that k−1≤sdiamk(G)≤n−1. In this paper، graphs with sdiam3(G)=2،3،n−1 are characterized، respectively. We also consider the NordhausGaddumtype results for the parameter sdiamk(G). We determine sharp upper and lower bounds of sdiamk(G)+sdiamk(G) and sdiamk(G)⋅sdiamk(G) for a graph G of order n. Some graph classes attaining these bounds are also given.
Keywords: Diameter; Steiner tree; Steiner kdiameter; complementary graph
  
 Module homomorphisms from Frechet algebras H. Shayanpour * Pages 455466 Abstract Full Text [PDF 126KB]   We first study some properties of Amodule homomorphisms θ:X→Y، where X and Y are Frchet Amodules and A is a unital Frchet algebra. Then we show that if there exists a continued bisection of the identity for A، then θ is automatically continuous under certain condition on X. In particular، every homomorphism from A into certain Frchet algebras (including Banach algebra) is automatically continuous. Finally، we show that every unital Frchet algebra with a continued bisection of the identity، is functionally continuous.
Keywords: Automatic continuity; Frchet algebras; module homomorphism; continued bisection of the identity; Frchet Amodule
  
 On convergence of sample and population Hilbertian functional principal components A. R. Soltani * , A. R. Nematollahi , R. Nasirzadeh Pages 467475 Abstract Full Text [PDF 112KB]   In this article we consider the sequences of sample and population covariance operators for a sequence of arrays of Hilbertian random elements. Then under the assumptions that sequences of the covariance operators norm are uniformly bounded and the sequences of the principal component scores are uniformly sumable، we prove that the convergence of the sequences of covariance operators would imply the convergence of the corresponding sequences of the sample and population eigenvalues and eigenvectors، and vice versa. In particular we prove that the principal component scores converge in distribution in certain family of Hilbertian elliptically contoured distributions.
Keywords: Hilbertian random elements; functional data analysis; functional principal component analysis; covariance operators; operator convergence.s
  
 Digital BorsukUlam theorem G. Burak , I. Karaca * Pages 477499 Abstract Full Text [PDF 194KB]   The aim of this paper is to compute a simplicial cohomology group of some specific digital images. Then we define ringand algebra structures of a digital cohomology with the cup product. Finally، we prove a special case of the BorsukUlam theorem fordigital images.
Keywords: Digital simplicial cohomology group; cup product; cohomology ring; cohomology algebra
  
 A characterization of simple K4groups of type L2(q)and their automorphism groups J. Li * , D. Yu , G. Chen , W. Shi Pages 501514 Abstract Full Text [PDF 132KB]   In this paper، it is proved that all simple K4groups of type L2(q) can be characterized by their maximum element orders together with their orders. Furthermore، the automorphism groups of simple K4groups of type L2(q) are also considered.
Keywords: Simple K4groups; maximum element order; characterization
  
 Pullback Dattractors for nonautonomous partly dissipative reactiondiffusion equations in unbounded domains X. Li * Pages 515534 Abstract Full Text [PDF 168KB]   At present paper، we establish the existence of pullback Dattractor for the process associated with nonautonomous partly dissipative reactiondiffusion equation in L2(Rn)L2(Rn). In order to do this، by energy equation method we show that the process، which possesses a pullback Dabsorbing set، is pullback D0 asymptotically compact.
Keywords: Pullback attractors; partly dissipative; reactiondiffusion equations
  
 Comparative study on solving fractional differential equations via shifted Jacobi collocation method M. Behroozifar * , F. Ahmadpour Pages 535560 Abstract Full Text [PDF 284KB]   In this paper، operational matrices of RiemannLiouville fractional integration and Caputo fractional differentiation for shifted Jacobi polynomials are considered. Using the given initial conditions، we transform the fractional differential equation (FDE) into a modified fractional differential equation with zero initial conditions. Next، all the existing functions in modified differential equation are approximated by shifted Jacobi polynomials. Then، operational matrices and spectral collocation method are applied to obtain a linear or nonlinear system of algebraic equations. System of algebraic equations can be simultaneously solved (e.g. using Mathematica^{TM}). Main characteristic behind of the this technique is that only a small number of shifted Jacobi polynomials is needed to obtain a satisfactory result which demonstrates the validity and efficiency of the method. Comparison between this method and some other methods confirm the good performance of the presented method. Also، this method is generalized for the multipoint fractional differential equation.
Keywords: Fractionalorder differential equation; RiemannLiouville integral; Jacobi polynomial; collocation method
  
 Separating partial normality classes with weighted composition operators H. Emamalipour , M. R. Jabbarzadeh * , Z. Moayyerizadeh Pages 561574 Abstract Full Text [PDF 145KB]   In this article، we discuss measure theoretic characterizations for weighted composition operators in some operator classes on L2(Σ) such as، npower normal، npower quasinormal، kquasiparanormal and quasiclass A. Then we show that weighted composition operators can separate these classes.
Keywords: conditional expectation; weighted composition operator; npower normal; kquasiparanormal
  
: 25/1/96 : 88808855 88807775 (021)
: 26/2/96
Ϙϐ : 170




